Such auxiliary means are known in my aforesaid application and are formed by glasses provided for restricting the initial input of visual information to either the right or left hemisphere of the brain. Those glasses have lenses that are opaque in a vertical portion. By restricting the initial input to one side of the brain, information crossover between the brain hemispheres is limited and processing of information in the brain of an individual who does not have a clear lateralization of function is improved.
Weak cerebral dominance has been proposed as an important factor in reading disability. From existing evidence, it appears that information gained, through reading, is processed by the dominant side of the brain, that is, mostly by the left side of the brain in right-handed people and mostly by the right side of the brain in left-handed people. Many individuals with reading disabilities are left-handed. Estimates are that as many as 70% of left-handed individuals have some degree of reading disability. This has been taken by some investigators as an indication of possible mixed dominance in brain function.
Experiments applied on individuals having visual and/or brain disorder has shown that individuals without a clearly dominant brain hemisphere have what may be termed cross-talk between the two hemispheres which may interfere with the efficient processing of reading material. It is thus important to be able to diagnose and treat reading disabilities that involve the improper directing of visual information to the hemispheres of the brain.
It is well established that retinal processing of visual information is almost entirely laterilized. The left half of the retinal field from the left eye and the left half of the retinal field from the right eye project to the left brain. The right half of the retinal field from the right eye and the right half of the retinal field from the left eye project to the right brain.
A drawback of the use of glasses having an opaque portion is that the glass lenses do not follow the eye movement of the person wearing the glasses, thus allowing some visual input to reach the supposedly blocked portion of the retina. Experiments have further shown that, even if the person would keep his head fixed, some visual and/or brain disorder remained, the latter may have a bad psychological influence on the person.
It is an object of the present invention to provide an improved auxiliary means wherein the drawbacks of the known auxiliary means are mitigated.
An auxiliary means according to the present invention is therefore characterized in that said optical element comprises at least one contact lens provided with orienting means affording said optical element a substantially stable orientation with respect to an eye wearing said lens, said occluded part being dimensioned in order to occlude at least 50% of the visual input. The use of contact lenses provided with orienting means enables the lenses to follow the eye movement of the person wearing the auxiliary means. The orienting means causes the contact lens to rotate on the wearer's eye putting the occluded part in proper orientation. Experiments have shown that visual information is processed in the back of the cortex and then transferred to the temporal lobe. The interpretation of the information is realized by the temporal lobe. Blocking the information transfer from the back of the cortex of the non-dominant hemisphere to the temporal lobe, avoid "crosstalk" between the two hemispheres. The use of a lens enables a more precise occluding of the eye and thus strictly limits the information transfer to the appropriate part of the dominant hemisphere. In such a manner, interfering information will not be produced which would otherwise disturb the interpretation realized in the temporal lobe.
It has to be noted that contact lenses having automatic orientation means are known in the art, for example from U.S. Pat. No. 3,431,327 and U.S. Pat. No. 3,279,878. The 3,431,327 patent discloses a bifocal contact lens that is formed with a small metal weight near one edge. The 3,279,878 patent discloses a lens that is thicker at one peripheral portion. The lens again rotates until the heavy thicker portion is at its lowest position, with the horizontally split field properly aligned. However none of these documents discloses the use of contact lenses with an occluded part and being suitable for the treatment of visual and/or brain disorder.
Tinting of contact lenses, both for cosmetic purposes or for lessening light input to sensitive eyes is also known, although no occlusion takes place, merely lowering of the light intensity. Of course, these lenses do not completely block visual input on any part of the lens and could not be used to selectively block input to vertical hemispheres.